The Overall Structural Conceptual Design And Strength Analysis Of Extended Tension Leg Platform

As a large and complex structure for mud oil and living supply, because of its tough work environment and complex structure, it is the core of this thesis's attention to carry on structural design and to analyze the strength ,as well as to describe the related questions detailedly and accurately.In this thesis, the Extended Tension Leg Platform(ETLP) is a comparison platform of the state 863 program"3000 meters deep-water semi-submersible drilling platform". This thesis introduces the structure characteristic of ETLP, carries out the conceptual design of ETLP, and establishes the geometric figures of the platform after separation by CAD. With software ANSYS, a 3D finite element model is established. According to the sea conditions of the South China Sea and the corresponding norms, this thesis calculates the environmental loads, and the wave load is calculated by the wave program WAFDUT1.3 of Dalian University of Technology.It determines the status of the load combination and checks the structural strength of ETLP by load resistance factor design method (LRFD) according to norm of DNV. It calculates Von Mises stress of the platform under operating status and limit self-existence status, and finds the solutions of every working situation one by one. The result is sorted out in the form of graphics and data tables and then analyzed correspondingly. This thesis also analyzes the natural frequency and vibration mode of the structure and confirms the result that the natural frequency of the platform is on the two sides of the first-order frequency spectrum and avoids resonating.In this thesis, the conceptual design of ETLP and the method and entire procedure of the whole structural strength analysis are discussed in detail. It has reference value for the similar problems.